1. Field of the Invention
The present invention relates to a device for simultaneously cutting-off viscous stock materials, such as, filler materials or putties and hardener pastes, that are dispensed from can-shaped containers having a displaceable pressing cover and being provided with closable discharge orifices. The containers are disposed in a supporting frame or structure which is provided with centering mounting means for the containers and an extrusion means having simultaneously operable piston rods. The piston rods have piston plates at the ends thereof which are displaceable in the interiors of the containers in a direction toward the discharge orifices of the containers.
2. Description of the Related Art
It is often considered disadvantageous that it is sometimes not possible to completely empty especially can-shaped containers whose contents weigh several kilograms and which contain viscous materials, more particularly filler materials and putties. If the containers can be emptied, emptying the containers requires a considerable amount of work and additional tools, such as, spatulas or the like. However, this additional work is usually not carried out, so that residues of the contents remain in the containers and are subsequently discarded with the containers. Added to this is the fact that, in some designs, the contents of the containers are very difficult to manipulate because of the highly viscous consistency of the materials. In addition, in some designs, it is considered a disadvantage that the application of stock material and hardener paste onto a spatula always takes place in such a way that the two materials must subsequently be mixed together.
Since the discharge apertures of the containers containing the filler material and the hardener paste are sometimes located fairly far apart, it may happen that a portion of the materials to be mixed flows past the spatula which has relatively small dimensions.
Numerous devices have been developed for dispensing two-component materials.
DE-A 25 37 002 discloses a hand-held dispenser for two-component materials with cartridges containing disposable material, with a disposable mixing head and with disposable connecting lines. This dispenser includes a pair of cartridges, accommodation spaces for the cans which, on oppositely located ends, are open through one end for receiving the cartridges containing and for dispensing the material. The other end of the cartridge extends through the oppositely located end of the can. A cartridge piston is disposed within the region of the one end of the can. The device further includes a piston assembly with a pair of piston heads provided on the ends of a pair of piston rods and interconnected for moving simultaneously, and a basic assembly for moving the piston heads into the operating position relative to the cartridge pistons. Also provided is a mixing head attaching and mounting assembly for the detachable attachment and mounting of the mixing head, wherein the two cartridges, the mixing head and the connecting lines for dosing, mixing and dispensing the two-component materials communicate with the dispenser and can be removed after use for the reuse of the dispenser with replacement cartridges. The device also has a replacement mixing head and replacement connecting lines, whereby a manipulatable and portable mixing and dispensing means is to be provided, with the aid of which a large number of two-component materials can be readily dosed, mixed and dispensed in larger quantities than had been possible in the past from a single cartridge, in order to make it possible to use inexpensive disposable cartridges and other disposable component parts which can be made available in the form of a kit for repeated use with the device.
The known hand-held dispenser for two-component materials has a construction in which two socket-like accommodation chambers are provided for the cartridges in a mounting means, wherein, after the cartridges have been inserted into the accommodation chambers, the cartridges are swung toward a supporting plate by means of hinge-like mountings, so that the cartridges are located in the path of advance of the pressing plungers. The discharge apertures of the cartridges or of the mounting means which project over the cartridges communicate via pipelines with a dispensing nozzle, wherein the dispensing nozzle is constructed in the form of a dispensable nozzle and is replaced by a new one after use.
It is a disadvantage in this known dispenser that, after the cartridges are emptied, the mixing heads are filled with filler material and hardener paste deposits which, when the dispenser is not operated for some time, become encrusted or harden, so that it will then be necessary to replace the mixing head. In addition, in this known dispensing means for two-component materials, the pipelines for conveying the material to be pressed out are not disposed on the supporting structure, but on the aperture projection of the container itself, so that the problem of sealing between the supporting structure and container does not arise. There is also no problem when the containers dispense the pressed-out material directly without the interposition of a further pipeline.
U.S. Pat. No. 3,957,176 shows a device for mounting a container with a filling means provided at the bottom part of the container for dispensing the container contents. This known device has a floor rack having two supporting members proceeding parallel to each other as support for the container. Lateral lugs or studs delimit the container set up in this manner, wherein the container is positionally secured with the aid of a set screw. The dispensing of the container contents is effected by the employment of compressed air. For this reason, the cover portion of the container has a rigid and airtight connection for the required pressure line, while the bottom portion of the container is provided with an opening as the discharge aperture constructed in the form of a threaded pipe portion. In this known device, it is disadvantageous that the filling means must be connected to the respective container to be emptied within the region of the discharge aperture in the bottom portion of the container. Since the filling means is attached to the bottom portion of the container, an alignment and centering of the container to a filling means rigidly secured in the supporting structure is not necessary because the latter forms a part of the container. Accordingly, the filling means is not a permanent component part of the means for carrying the container, but constitutes a special part which, when the container is to be used, has to be placed upon the circumferential rim delimiting the discharge aperture. However, viscous filler materials can only be pressed out of the container or cartridge by employing a high pressure. The larger the container dimensions, the greater the pressure that has to be applied will be. A filling means which is merely mounted on the rim forming the discharge aperture can subsequently easily become leaky within the connecting area, especially when it becomes necessary to make use of high pressures for squeezing out the container contents. In contrast, when the attachment of the filling means is effected with the aid of a screw thread on the bottom portion of the container, a relatively great effort is necessary for preparing the container for operation.
IT-A-834 936 shows a device for accommodating three cartridges, wherein the contents of the three cartridges can be pressed out simultaneously. This known device has a supporting frame with centering mounts for the cartridges containing the materials to be dispensed and a squeezing-out means with simultaneously operable piston rods with piston plates disposed at the ends thereof and displaceable in the interiors of the cartridges toward the centering mounting means, wherein the cartridges to be employed in this device have a cross-sectional configuration and dimensions corresponding to those of the centering mounting means. Dispensing of the materials from the cartridges, not shown in IT-A 834 936, is probably effected by means of nozzle-like discharge apertures similar to those shown in DE-A 25 37 002, wherein the discharge apertures of the three cartridges are disposed so as to be spaced apart fairly far, so that, when the materials to be mixed are dispensed onto a spatula, a portion of the materials will flow past the spatula which has relatively small dimensions. In addition, this device is operated manually and each individual cartridge has to be provided with a discharge sleeve because the mounting of the cartridges in the device is not effected exclusively by the supporting frame structure, but with the aid of the discharge sleeves on the cartridges which are retained in recesses of the end plates of the supporting frame of the device.
What is disadvantageous in this device is the fact that the device is exclusively operated by hand and that, following the termination of the squeezing-out operation, material still continues to flow from the cartridges and this subsequent flow can only be stopped by discontinuing the pressure of the pressing piston acting on the material by withdrawing the main piston rod.
U.S. Pat. No. 4,033,480 describes a device for simultaneously dispensing two different media from two separate containers. This device includes a base plate with two openings that communicate with delivery or outlet valves. Two containers are disposed on the base plate, wherein the bottom of each container is provided with a discharge aperture. Within the region of these discharge apertures, the bottoms of both containers have externally located studs, such that the studs engage into the openings in the base plate when the container is disposed on the base plate. The stirrup-like locking means provided in this device do not serve exclusively for positionally securing the two containers on the base plate, but also for the retention of the cover portions of the two containers on the containers themselves since the entire device is operated with the aid of compressed air. A piston plate is disposed in each container above the material contained therein. The piston plate can be acted upon by compressed air, so that the materials can be pressed out of the two containers after the discharge valves have been opened.
This device has the disadvantage that the piston plates in the interiors of the two containers are actuated by means of compressed air. It is possible that compressed air will flow through the interspace between piston plate and container wall since a complete sealing within the marginal area of each container is problematic. That is why, when emptying the containers down to the last material residue, it cannot be avoided that this residue is pressed out of the opened delivery valves at a relatively high pressure, so that splashing or spattering of the material flowing out of the containers may occur.
In addition, in the known device, the two containers are centered on their base plates solely by means of their studs. Each container is merely placed upon its base plate and the container has to be displaced until the stud provided within the region of the bottom discharge aperture of the container engages into the opening of the base plate. Particularly, when large-volume containers having a relatively great weight are involved, this is a relatively laborious procedure to shift the container on its base plate until, by pure chance, the opening in the base plate is found, so that the external stud in the area of the discharge aperture in the bottom portion of the container engages into the opening of the base plate.
The containers used in this device have studs on the container bottom plates, wherein the studs are formed externally within the region of the container bottom discharge apertures. Consequently, the stud is not located in the plane formed by the bottom plate of each container. As a result, containers constructed in this manner cannot easily be placed on their bottom sides so as to stand upright on an even surface. Moreover, it is difficult to stack the containers constructed in this manner one on top of the other. The cover portions of the containers are detachable and, due to the use of compressed air, the cover portions have to be retained so as to fit firmly on the container bodies, which is effected with the aid of the stirrup-like or bracket-like arresting means.
Due to the external stud provided in the containers of this device within the region of the bottom discharge apertures, it is possible, when large and heavy containers are involved, that the entire bottom portion may be pressed in when the containers are put down on a plane surface, so that the external stud provided within the region of the bottom discharge aperture comes to lie in the plane which is formed by the circumferential rim of the bottom plate of the container, so that, in turn, after a container damaged in this manner is placed on the base plate of the device, the stud is no longer capable of engaging in the openings of the base plate and, when the device is operated for dispensing material, the material may run out between the bottom portion and the base plate and harden there. Encrustations may form in this area and it cannot be excluded that hardened material particles find their way into the material to be pressed out.
Furthermore, in this known device, the delivery valves for the two containers are disposed at a relatively great distance from each other, so that the materials from the two containers cannot be pressed out in such a way that they are located close to one another. Due to the fact that a pressurization of the pressing-out pistons takes place by means of the gas pressure, the containers are fixed by transmitting the pressing force of the pressing pistons to the container bottoms, wherein the container bottoms are pressed against the base plates by the pressing force. However, the gas pressure forces acting on the container covers must be supported and absorbed by screwing buttons and clamping brackets on the supporting frame. However, in order to render this additional pressing on by the pressing forces effective, the container covers must not be connected with positive engagement to the containers because otherwise the gas forces acting upon the container covers would not allow the pressing forces required for the fixation to become effective. Rather, the container covers must be pressed in a gas-tight fashion against the containers with the aid of the screw bottons and clamping brackets secured to the supporting frame. In this device, a sealing of the thread of the container covers by means of clamping brackets is always necessary.
All these known dispensing devices for two-component materials have in common that expensive constructions are necessary and the mixing and dosing heads have to be thoroughly cleaned even after a brief period of use and operation of the devices in order to prevent that small hardened material particles penetrate into the material to be pressed out which would lead to a reduction of the quality of priming operations carried out with the material or would require additional grinding operations of the hardened surfaces.
Therefore, it is the primary object of the present invention to provide a device of the above-described type which is simple to handle and inexpensive to manufacture and can be used in the form of a disposable article. It should be possible by means of the device to simultaneously dispense filler materials and hardener pastes and to mount the device on the discharge apertures of the can-shaped containers containing the filler material and hardener paste. At the same time, when the device is mounted on the containers, the device should seal the discharge apertures of the containers.